The Concept of Justice in Greek Philosophy
Abstract
The Greeks looked upon justice as a virtue in action, and therefore a virtue. The Greek conception of justice was the virtue of the soul, and injustice its vice. To both Plato and Aristotle justice meant goodness as well as willingness to obey laws.

It connoted correspondence of rights and duties. Justice was the ideal of perfection in human relationships. And the spirit which animated men in the proper discharge of their duties. The promotion of balance and harmony in thought and action was pre-eminently social in character. Nature was the source of law and the duty of the state was ordinarily considered to be the application rather than the creation of the law.

Aristotle, and Plato's justice, in fact, are complementary to each other. The aim of both philosophers is to find a principle of capacity through which unity, harmony, virtue, and happiness can be established in society. But in spite of this common agreement, they differ in many fundamental respects from each other. This study will examine Plato's and Aristotle's theories of justice and then make a comparison between them.

Introduction
Justice has been one of the important issues in the history of philosophy. The Greek conception of justice was the virtue of the soul and action. To both Plato and Aristotle, justice meant goodness as well as willingness to obey laws. It connoted correspondence of rights and duties. Justice was the ideal of perfection in human relationships.
To Plato, "justice was one of the highest of virtues".

(Bhandari, 2002)
Justice, to the Greeks, was the spirit that animated men in the proper discharge of their duties. The promotion of balance and harmony in thought and action was pre-eminently social in character.

To the Greeks, "the city-state was both a church as well as a political institution, and its end was to promote among its citizens' goodness and justice, the latter representing an ideal perfection in human relationships". (Bhandari, 2002) This part deals with the theories of Plato and Aristotle as follows

Note:
"The Greeks were devoted to their laws partly because of the belief in their superhuman origin and partly because the general principles embodying the law were believed to be perfect and permanent and not subject to change at the will of the people. Nature was the source of law and the duty of the state was ordinarily considered to be the application rather than the creation of the law. Law, to the Greeks, was moral because it was natural and, therefore, it constituted the cement of the city-state. Law was the same for all and, therefore, in a way, it meant freedom. Obedience to laws was an essential element in the Hellenic conception of liberty".

Plato's Theory of Justice
After Socrates, "Plato, also regarded justice as the true principle of social life". And he has named his most important work. Republic, as a discussion on justice. Dr. Barker, therefore, has pointed out that "Justice is the hinge of his thought". (Barker, 1952)

In his contemporary world, Plato saw states everywhere cities so divided that their citizens stood "in the state and posture of gladiators" against one another. He saw unrighteousness rampant and injustice enthroned. He saw ignorance supreme and parading up and down in the guise of knowledge. (Wayper, 1954)
Plato in his theory of state mentions that there are five types of political organizations:
aristocracy, the rule of the best;
timocracy, in which the rulers are motivated by honor;
oligarchy, in which the rulers seek wealth;
democracy, the rule of the masses;
tyranny, the rule of one man advancing solely his own selfish interests.

Plato's theory of Ethics

In his theory of Ethics, Plato held that the soul is in essence rational and immortal. The world of true beings, the world of ideas, is the source of all its goodness. The body is material and is the ground of all evil. It is only a temporary prison house.

Release from the body and contemplation of the beautiful ream of ideas is the ultimate goal of life. The embodied soul is wise if reason rules all its impulses. It is brave if its spirited part aids and obeys the rational part, temperate, if both spirit and appetite obey the dictates of reason, and just. If all the three parts perform their respective functions in unison.

Aristotle's Theory of Justice
Aristotlewas born at Stagira in Thrace in 384 B.C. and he died in 322. He was the greatest of Plato's disciples and he took his inspiration on many things from his celebrated teacher. Aristotle believed, like his master, Plato, that justice is the very essence of the state, and that no polity can endure for a long time unless it is founded on a right scheme of justice.

It is with this consideration in view that Aristotle proceeds to set forth his theory of justice. The theory, however, was not developed by him in isolation. The Republic of Plato serves as a great guide Generally, Aristotle believes that everything has a special aim, and man's special aim is to reach real happiness. He sat the concept of human happiness basis of his discussion and explains the concept of justice on the basis of individual life.

Justice relation

Justice is relative to persons, and a justice distribution is one in which the relative values of the things given correspond to those of the persons receiving.

According to Aristotle, justice in an individual is harmony in the human soul, and in society is equality and proportion in the enjoyment of values.
In Aristotle's political philosophy, the essential criterion of justice is treating equals equally and un-equals unequally but in proportion to their relevant differences.

He says in his Politics: "In all sciences and arts the end is a good, and especially and above all in the highest of all – this is the political science of which the good is justice.

In other words:
the common interest. All men think justice to be a sort of equality; and to a certain extent, they agree in the philosophical distinctions which have been laid down by us about Ethics. For they admit that justice is a thing having relation to persons, and that equals ought to have equality. However, there still remains a question – equality or inequality of what? Here is a difficulty which the political philosopher has to resolve". (Aristotle, 1953)

The ethical goal of happiness
The ethical goal of happiness cannot be attained without some non-ethical prerequisites, such as the proper discharge of mental and bodily functions and the satisfaction of economic needs.

Human happiness manifests itself in two ways: first in the habitual subordination of the animal side of man's nature, his appetites, desires, and passions, to rational rule; secondly, in the exercise of reason in the search for knowledge and contemplation of truth.

In the former case, happiness expresses itself in moral virtues (courage, temperance, liberality, magnanimity, love of honor, mildness, truthfulness, friendship, and the highest of them all, justice).
In the latter case, it manifests itself in intellectual virtues which are of two types:
those of theoretical reason which we use in our inquiry in the nature of what is necessary and in the intuitive apprehension of truth (science and reason), and
those of practical reason by which we exercise deliberation in such matters as is possible for us to change (art and practical wisdom).

Conclusion
Aristotle's and Plato's justice, in fact, are complementary to each other, but they differ in many fundamental respects from each other. For example, Aristotelian justice lays emphasis on a system of rights, while Platonic justice attaches more importance to duties.

The Aristotelian justice is based, as it were, on the principle that "everyone should have his own". The Platonic justice, on the contrary, is based on the principle of "everyone should do his own".

The former, therefore, is a system of rights but the latter is a system of duties. Also, Aristotelian justice establishes equality between different members of the state, while Platonic justice establishes a hierarchy of classes.